Alkylsilahydrocabbons



Patented June 13, 1950 ALKYLSILAHYDROCARBONB John T. Goodwin, Jr.,Pittsburgh Pa., usignor to Midland,

Dow Corning Corporation,

higan corporation oi Mic No Drawing.

Mich. a

Application April 20, 1948, Serial No. 22,251. In Great Britain July 1,1947 2 Claims. (Cl. 260-4483) The present invention relates to neworganosilicon materials. i

' In the history of the organosilicon compounds, two principal types ofcompounds containing more than one silicon atom have heretofore beendescribed. In one of these types, the silicon atcm are linked directlyto each other. These are the so-called polysilanes heretofore describedby Kipping. The present organosilicon industry is based upon thesiloxanes which are materials in which the silicon atoms are linkedthrough oxygen atoms. There has been some mention in the literatureheretofore or organosilicon halides containing a plurality of siliconatoms in which the silicon atoms are linked by large divalent organicradicals and the remaining valences of the silicon atoms are satisfiedby chlorine.

Objects oi the present invention are the provision of new compoundswhich are of general utility industrially.

Compounds in accordance herewith are of the formula RISlRaCHzhSlRa inwhich R represents alkyl radicals such as methyl to oetadecyl and nrepresents a positive integer.

The compounds hereof are fluids. Those of relatively low molecularweight are distillable. The higher molecular weight materials aregenerally non-distillable. The thermal stability of the presentcompounds is comparable to that of siloxanes. The stability of thesecompounds at high temperature in the presence of steam is substantiallybetter than the stability of siloxanes under equivalent conditions.

The present compounds may be prepared by various methods. Thus compoundsof the type ClESiChC HzhSiCh may be reacted with a Grig .nard reagentprepared from an alkyl halide,

whereby to substitute alkyl radicals for th chlorine atoms.

Likewise these compounds have been prepared by contacting a compound ofthe type RaSiCHaCl with an alkali metal in the presence of a compound oithe type RaSiCl. Where R. is methyl.this produces 2.2,4,4tetramethyl-2.4 disilapentane. (CH1) :SiCHiSKCHs) 3. pounds 01' thistype by this general method but in which compounds n is greater thanone. a compound of the type RiSiRzCI-InhCl may be substituted for thecompound RaSlCI-IaCL By this In order to produce coma method the largerlinear compounds have been lo produced. These general methods aredisclosed in my copending applications Serial Nos. 22,253, new Patent2,507,512 and 22,254, new Patent 2,507,513, filed simultaneouslyherewith.

The production or the present compounds may be by interacting a compound0! the type C1 [SlRmCI-IzhSiR-aCl with an alkyl Grignard reagent. Theproduction of this organosilicon chloride is disclosed in my copendingapplication Serial No. 22.252, filed slmultaneously herewith.

The compounds hereoi are of utility for such purposes as hydrophobingagents, lubricants, hydraulic fluids and the like.

The following examples illustrate the method oi the present invention.

Example 1.6l parts by weight of (CH3) 3SiCHzC1 parts of (CHahSiCl andparts of hen decane were placed in a reaction vessel and heated untilrefluxing occurred. 23 parts by weight of metallic sodium were addedslowly in small pieces while stirring the reaction mixture. The reactionproceeded slowly at first due to the low reflux temperature. As thereaction occurred and the reactants were used up, the temperature roseand the reaction rate increased. The products were distilled from thereaction mixture until the boiling point indicated that hexadecane wasstarting to be distilled. The distillate was redistilled whereby 52parts of a material boiling at l32.2 C. at 740 mm. were obtained. Thismaterial was found to be 132.2 0. at 740 mm.... 1.41

l Molar retraction blood on paper by li. L. Wan-ink .08 am am).

Example 2.Eighty-seven parts of Z-ethoxy- 2,4,4,6,6-pentamethyl 2,4,6trisilaheptane were reacted with 65 parts of methyl magnesium bromide in142 parts of absolute ether. The ether was distilled off through acolumn and the reactants were heated at 190 C. for 14 hours. Salt wasdeposited durin the heating. The reaction product was poured into anaqueous hydrogen chloride solution and the non-aqueous layer wasrecovered. This layer was dried, filtered and dism tilled. The compoundobtained was (cm nsaomsi (CH3) 2CHzSflCH3) =5 and had a boiling point of208 C. at atmospheric pressure, a freezing point of -64 C. and a densityw of 0.7990 at 25 C. A 46.4 percent yield was obtained.

were added to 69 parts of methyl magnesium bro- 20 mide in 142 parts ofabsolute ethen Theprepae ration was conducted as in Example; 2; An.89.-per cent yield of CH: [SHCHal 2CH2]:Si(CHa) 3 was obtained. This productdistills at 187 at 19mm;

has a freezing point of--l10 and a density of a 0.8210 at 25= C.

Example 4..Fifteen parts of 11a whichkmrearesents alkyl and n is apositive integer.

2. Compounds in accordance with claim 1 in which R. represents methyl.

JOHN T. GOODWIN, JR.

REFERENCES CITED The tnllowmg references are of record in the UNITED:SEATES PATENTS Name Date Rochow July 4, 1944 OTHER REFERENCES Sommer et'111., "Four. Am. Chem. Soc.,"vo'l; 69,

Number April. 1947.. page 980, article received. Maren. 6.

1. COMPOUNDS OF THE GENERAL FORMULA